Not sure how to describe but on the third to fifth shot the trigger hesitates before the round goes off. I tried two different primers to see if that was it but that was not it. I think! There is a round mark appearing on the flat side of the rim near the primer. I cleaned the gun well before the last but it didn't seam to matter. I'm not a gun smith and don't have time to take it to one before my CO trip. I have a back up gun a 340 Wetherby from my uncle. But I wanted to use my Rem 700 300rum. Any ideas what it could be? Thanks

a few questions, is it a bolt gun? and is it new?have you tried different ammo if it is a bolt gun and new there might be a defect in the firing pin, or it might be bad ammo, but i doubt it. you said there is a mark on the rim just outside the primer, maybe the pin hits the rim then slides onto the primer which would cause a a delay and leave a mark. i am not a gunsmith either but that seems to make sense, if you can buy a new bolt assembly that might be cheaper than taking it to a gunsmith for a diagnostic, you said youve tried different primers does that mean you handload your own ammo, and if so do you use old brass with new primers or do you buy brass,primers,projectiles,and powder seperately and put em together, i dont think this is the problem because a consistantly bad primers is way less likely than, play in the firing pin assembly, if its a gun you've used for a while and this just started to happen i still think that points to a worn out part be it a spring or what have you, i hope this gives you things to look at and think about.

a few questions, is it a bolt gun? and is it new?have you tried different ammo if it is a bolt gun and new there might be a defect in the firing pin, or it might be bad ammo, but i doubt it. you said there is a mark on the rim just outside the primer, maybe the pin hits the rim then slides onto the primer which would cause a a delay and leave a mark. i am not a gunsmith either but that seems to make sense, if you can buy a new bolt assembly that might be cheaper than taking it to a gunsmith for a diagnostic, you said youve tried different primers does that mean you handload your own ammo, and if so do you use old brass with new primers or do you buy brass,primers,projectiles,and powder seperately and put em together, i dont think this is the problem because a consistantly bad primers is way less likely than, play in the firing pin assembly, if its a gun you've used for a while and this just started to happen i still think that points to a worn out part be it a spring or what have you, i hope this gives you things to look at and think about.

Yes Rem. 700 300 Ultra Magnum. 2 Yr old. Tried Rem. Fed., and Winchester with no problems. The primer looks good, the mark is on the lettering. I used once fired brass and new brass with new primers less the one year old. Thanks